In America, politicians write autobiographies; in France, political manifestoes; but in Britain, statesmen tend towards biography. Roy Jenkins outlined his liberal ancestry with the lives of Asquith, Gladstone and Churchill. Michael Foot anointed himself Labour's radical heir with his biography of Bevan. And now William Hague is re-establishing his claims to the Tory leadership with a history of William Pitt the Younger.

In terms of position publishing, this was a no-brainer: "Billy the Kid" on "Master Billy". Both young political obsessives, brilliant orators, occasional boozers, and both gifted the party leadership at precocious ages. The difference, of course, is that Pitt made it into Downing Street.

Born in 1759 the son of William Pitt, Earl of Chatham, Pitt was bred at an early age for office. As Hague read Hansard in his teens, so Pitt spent his childhood delivering speeches to an imaginary House of Commons. And it is the corridors of Westminster that dominate this history.

While the Industrial Revolution is shaking Britain and the Enlightenment presaging new mental horizons, Hague's biography ambles through endless plots, factions and coups - just the kind of political navel-gazing that has bedevilled the Conservative party for the last 15 years.

Aged 24, Pitt became prime minister in 1783, and kept the post until 1801. What were the achievements of those years? Hague the consummate political hack is instantly drawn to Pitt's programme of party re-alignment as he converted a weak coalition into a two-decade strong government. But while Hague the ex-McKinsey's management consultant is full of ardour for Pitt's administrative reforms, he is equally admiring of Pitt the wartime prime minister.

Hague's selling point as a biographer is to enlighten this well-documented history through "the eyes of a politician". But what is conspicuously lacking is a discussion of Tory thinking. Pitt is regarded as the father of modern Conservatism. Curiously, the book avoids exploring this intellectual legacy, or what it might mean for today's Tories.

In the absence of ideology, we are offered a celebration of Tory leadership in the form of effective parliamentary tactics. But this comparison does not work to Hague's favour. He was, after all, the leader who ennobled Conrad Black, backed Jeffrey Archer for mayor of London, gave excessive power to an unreconstructed party membership (so preparing the way for Iain Duncan Smith) and adopted a hapless Core Vote strategy which yielded only one extra seat in 2001. Pitt, on the other hand, was so successful that after his resignation in 1801 (over Catholic emancipation) he resumed power in 1804.

And the capacity to return to office is what hovers over the book. Under the guise of Pitt, William Hague comes across as likeable and intelligent, but with few ideas about the nature of Conservatism, its history or prospects. Maybe that was the true publishing conceit: the man who presided over the Tory party's death on the life of its founder. As much obituary as biography.

·Tristram Hunt is the author of Building Jerusalem: the Rise and Fall of the Victorian City.